I'll greatly appreciate it if someone can explain to me:
why the sheva on first mem is sheva nach in the following word: וּמְקַיֵם
I'll greatly appreciate it if someone can explain to me:
why the sheva on first mem is sheva nach in the following word: וּמְקַיֵם
I'm sure this has been hashed out before here already, and many of our users here are far superior grammarians, but ... here goes. We avoid starting a sentence with a double sh'va. Because to do so would be a conflict between the rule "first letter of a word is na" and the rule "double shvas, only the second one talks." (These are known as rules "Alef" and "Bet" of sheva na, respectively.)
So: מְקַיֵם : na.
So this would would have been וְמְקַיֵם . But we can't allow that. So the opening vav becomes "oo."
The question is then whether the shva should remain na, as it would have been if it opened the word, or now becomes nach, because we've avoided the issue and it essentially still pretends to be the second shva in a row.
This is a debate among grammarians (so you'll see different things in different places), but my impression is that nach ("resting") is the preferred opinion today. It's what you'll see in Rabbi Breuer's "Chorev" tiqqun, for example.